(Funded in part by an EMBL grant to T. Hyman). We are trying to cut through the vertical spindle of uni-cellular C. eleans (Nematode) embryos to estimate the forces acting on either spindle pole during anaphase B, both in wild-type and mutants. The laser is being used in attempt to sever the half spindle during metaphase. The embryo are then followed through mitosis with the position of the daughter tracked.